Write function utilizing function argument's template argument

Question

I want to write a function that takes an Eigen Spline , which is a templated class

Spline<typename _Scalar, int _Dim, int _Degree>

Is it possible (and how would I) to write a function which is not a member function of the Spline class that accepts a generic Spline and makes use of the _Scalar, _Dim, and _Degree variables? They are public enum s and a typedef .

Answer 1

Yes, write a function template:

template <typename T, int DIM, int DEG>
void foo(const Spline<T, DIM, DEG>& spline);

Note that I have removed all the names with leading underscores. Those are reserved names and it is undefined behaviour to use them. It seems Eigen is being naughty in this respect.

Answer 2

Make it a template function itself:

template<typename _Scalar, int _Dim, int _Degree>
void myFunction(Spline<_Scalar, _Dim, _Degree> &spline) {
  // do stuff...
}